Method of making a wound core and apparatus therefor

ABSTRACT

A magnetic steel strip is continuously fed into a cutting device which cuts the steel strip into a prescribed length. The cutting device is operated in response to a first metering device which meters the length of the magnetic steel strip to be cut, and cuts the steel strip into the prescribed length successively utilizing a compulsory hump forming device disposed at the feed-out side of the cutting device without stopping the feed of the magnetic steel strip. The cut magnetic steel strips are transferred to a feed-out device and further to a continuous winding device. By the winding device the cut magnetic steel strips are wound into a wound core in which the seam positions are overlapped by a prescribed length.

O Unite States Patent i 1 3,628,241

[ 72] Inventors gozogioyoda [56] References Cited UNITED STATES PATENTSK t t k t k, f [21] APPLNQ 2 2 Japan 3,223,955 12/1965 Olsen etal.zsleosx [22] Filed Apnzs 1970 3,362,066 1/1968 Cooper 29/605 [45]Patented Dec.2l,l971 Primary Examiner-Travis S.lVlcGehee [73] AssigneeHitachi, Ltd. Attorney-Craig, Antonelli, Stewart & Hill Toky0,Japan [32]Priority May 2, 1969 33 Japan ABSTRACT: A magnetic steel strip iscontinuously fed into a {31] 44/33611 cutting device which cuts thesteel strip into a prescribed [54] METHOD OF MAKING A WOUND CORE ANDlength. The cutting device is operated in response to a first meteringdevice which meters the length of the magnetic steel strip to be cut,and cuts the steel strip into the prescribed length successivelyutilizing a compulsory hump forming device disposed at the feed-out sideof the cutting device without stopping the feed of the magnetic steelstrip. The cut magnetic steel strips are transferred to a feed-outdevice and further to a continuous winding device. By the winding devicethe cut magnetic steel strips are wound into a wound core in which theseam positions are overlapped by a prescribed length.

SHEET 1 OF 4 COU/VTB? SCH/W77 79/6656 E52;g ME E w AMPL/F/El? INVENTORSDA and KATuros: AKAI'M W; Jaw d M ATTORNEY3 PATENTED necz'r I97! SHEET 2OF 4 w w 4 SI Q Q uwmi ffiwi INVENTORS K010 TovooA and KA TDsI AKA M M 7W41 m ATTORNEY) PATENTED DECZT 1911 3.62824 1- SHEET 3 OF 4 I INVENTOR$K010 TOYaDA and KAFUTOSI AKATM 4 M a W ATTURNEY BACKGROUND OF THEINVENTION 1. Field of the Invention The present invention relates to amethod of and apparatus for making a wound core used for an electricdevice such as a transformer, a current transformer for a meter and thelike.

2. Description of the Prior Art In general, the wound core used for anelectric device such as a transformer, a current transformer and thelike is formed by rolling a magnetic steel strip into a loop having aprescribed internal diameter.

There are two kinds of method of making a wound core according to theuse thereof. In one of the methods, a long magnetic steel strip isrolled a plurality of times into a loop having a prescribed internaldiameter with a winding device. In the other of the methods of makingthe wound core, a plurality of magnetic steel strips cut into variousprescribed lengths are wound in order into a loop having a prescribedinternal diameter with a winding machine.

In the latter method wherein the wound core is formed from a pluralityof steel strips, the steel strips are cut into the prescribed differentlength in advance. That is, in order to form a wound core which has nospacing between the convolutions, the respective pieces of the magneticsteel strips should have length computed. For example, in the case thatthe internal diameter of a wound core to be formed is D and thethickness of the steel strip is t, the magnetic steel strip wound in theinnermost convolution should have length of l,("-'rrD) and the steelstrip to be wound adjacent to the inner most one should have length of 1which is longer than 1 by 2 1. Thus, the magnetic steel strips woundinto the wound core should be cut into the length of 2 1" longer thanthe inner adjacent ones.

Accordingly, in the case of a wound core formed of n pieces of magneticsteel strips, there is a difference in length of 2 arm between thelength l of the piece of the magnetic steel strip in the innermostconvolution and the length 1,, of the piece in the outermost convolutionthereof.

In view of the above fact, in the conventional method of making a woundcore, a hoop-shaped magnetic steel strip has been cut with a steel stripcutter into pieces of steel strip having length differed by 2 wt inorder. In the steel strip cutter used in the method as above, a steelstrip carrier provided with a stopper for the steel strip is slidablymounted on a cutting board and the carrier is interlocked with a cutterso that the steel strip may be cut by the cutter when the steel strip isstopped by the stopper which is set at the prescribed position fordetermining the length of the piece of the steel strip to be formed intothe wound core. In this case, there is a disadvantage that the cuttingwork can not be performed with high efficiency since the steel stripcarrier should be moved to a different position every time it hascompleted cutting operation so as to change the length of the piece ofsteel strip to be cut in the next cutting operation.

Furthermore, there is such a disadvantage as follows in the conventionalmethod of making a wound core. in the case that the wound core isrequired to be mounted to a primary conductor of a current transformerof hairpin shape or to a winding which is formed separately, after thewound core is formed of a plurality of pieces of magnetic steel stripcut into different length, the seam positions in the respectiveconvolutions should be out of alignment with one other and be within arange so that the wound core may be easily formed and disassembled. Inthe conventional method of making a wound core, the winding operationcan not be made with high efficiency, since the pieces of the magneticsteel strip should be carefully introduced into the winding machinewhich is driven intermittently.

Under the above-described disposition of the conventional method ofmaking the wound core, a new and excellent method of and apparatus foreasily and rapidly making a wound core from a plurality of pieces ofsteel strip have been desired to be developed.

SUMMARY OF THE INVENTION The principal object of the present inventionis to provide a method of and apparatus for easily making a wound coreused for an electric device such as a transformer, a current transformerfor a meter and the like.

Another object of the present invention is to provide a method of andapparatus for making a wound core wherein a plurality of pieces of steelstrip of different length are wound into a roll of strip by making theseam positions therein be out of alignment, that is, be overlapped bythe prescribed dimension.

Still another object of the present invention is to provide a method ofand apparatus for making a wound core wherein at least two groups of aplurality of pieces of magnetic steel strip are wound into a wound coreand wherein the end of the first pieces in the respective groups arepositioned in alignment with each other so that the seam positions areall within a prescribed range in order that the wound core may be easilydisassembled.

A further object of the present invention is to provide a method of andapparatus for making a wound core wherein a plurality of pieces ofmagnetic steel strip can be continuously cut out with a cutter withoutstopping the feeding device and the feedout device for feeding a steelstrip from a hoopshaped magnetic steel strip supply.

A still further object of the present invention is to provide a methodof and apparatus for making a wound core wherein the cutting operationfor cutting out various length of magnetic steel strips from ahoop-shaped magnetic steel strip and the winding operation for windingthe strips into a core are performed in a serial operation.

The above and other objects and advantages of the present invention willbe made apparent from the following description of the preferredembodiments of the invention.

The features of the method of and apparatus for making the wound core inaccordance with the present invention lie in that the hoop-shapedmagnetic steel strip supported with a rotatable supporting device iscontinuously fed into a cutting device with a feeding in device, thefeeding in device is operated in response to a first metering devicewhich meters the length of the fed in steel strip, the magnetic steelstrip is successively cut into the prescribed length of pieces withoutstopping the feed-in operation utilizing a hump which is formed with acompulsory hump forming device disposed at the feed-out side of thecutting device, the hump forming device is actuated when the cuttingdevice is started to be operated and is retracted when the cuttingdevice finished operating, and the pieces of the steel strip aresuccessively fed out and transferred into a continuous winding devicewhich forms a wound core by overlapping the end of the strips so thatthe seam positions therein may be out of alignment, that is, the seampositions are overlapped.

BRIEF DESCRIPTION OF THE DRAWING HO. 1 is a front view of an example ofa wound core formed in accordance with the method and apparatus of thepresent invention in which the seam positions of the wound strips areall out of alignment with one another,

FIG. 2 is a front view of another example of a wound core formed inaccordance with another embodiment of the method and apparatus of thepresent invention in which the steel strips are divided into at leasttwo groups and the end of the first strip in the respective groups arepositioned in alignment with each other so that the seam positions maybe within a range in order that the wound core can be easilydisassembled,

FIG. 3 is a front view of still another example of a wound core formedin accordance with another embodiment of the method and apparatus of thepresent invention in which the same construction as that shown in FIG. 2is formed in a rectangular shape,

FIG. 4 is a front view of the superposed pieces of magnetic steel stripused for making a wound core as shown in FIGS. 2 and 3,

FIG. 5 is a front view of the superposed pieces of magnetic steel stripused for making a wound core with an end of the respective piecesaligned,

FIG. 6 is a schematic view of an embodiment of the method of andapparatus for making a wound core in accordance with the presentinvention,

FIG. 7 is a schematic view of the apparatus shown in FIG. 6 with thewinding device omitted at the state of cutting the magnetic steel strip,

FIG. 8 is a schematic view of another embodiment of the method of andapparatus for making a wound core in accordance with the presentinvention at the state of cutting the magnetic steel strip with thewinding device thereof omitted.

FIG. 9 is a front view of the supporting device for supporting thehoop-shaped magnetic steel strip used for the method of and apparatusfor making the wound core in accordance with the present invention,

FIG. 10 is a schematic front view showing the feeding in device, cuttingdevice, compulsory hump forming device and feeding out device for themagnetic steel strip used in the method of and apparatus for making thewound core in accordance with the present invention,

FIG. 1 l is a front view of the continuous winding device for the piecesof magnetic steel strip used in the method and apparatus in accordancewith the present invention, and FIG. 12 is a schematic view of anexample of the metering device employed in the method and apparatus inaccordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of and apparatus formaking a wound core in accordance with the present invention is appliedfor making such wound .cores as shown in FIGS. 1, 2 and 3 from ahoopshaped magnetic steel strip by cutting it into pieces and windingthem into a core. The wound core 1 shown in FIG. 1 is made of 10 piecesof steel strip 2 which all have different length and wound in ordersuccessively so that the seam positions may be all out of alignment withone another and the respective pieces may be lapped with the adjacentone by the length W. The wound core 1 shown in FIG. 2 is made of twogroups 1a, 1b of five pieces of magnetic steel strip 2. The five piecesof magnetic steel strip 2 are all different in length in the respectivegroups 1a, lb. The two groups are wound into a core wherein therespective pieces are lapped with the adjacent one by the length W andthe ends of the first strip in the respective groups are aligned witheach other so that the seams may be within a limited range in order thatthe core can be easily disassembled. The wound core 1 as shown in FIG. 2is formed in a rectangular shape as shown in FIG. 3 according to the usethereof.

The pieces of the magnetic steel strip 2 to be formed into a core 1 havedifferent length as shown in FIG. 5 and as set forth above in thedescription of the prior art. The adjacent pieces of the magnetic steelstrip 2 in the core 1 have difference in length of 2 m (t: thickness ofthe magnetic steel strip) and accordingly, the piece of the steel stripon the outermost convolution of the wound core is required to be cutinto a length longer than that in the innermost convolution thereof bythe length of m. In the present invention, such pieces of magnetic steelstrip 2 are successively cut out from a hoop-shaped magnetic steel stripand wound into a wound core automati cally.

The schematic process and construction of the basic part of the methodof and apparatus for making the wound core are shown in FIG. 6 and willbe described in detail referring thereto. The apparatus 100 shown inFIG. 6 cuts out prescribed different length of pieces 11a from ahoop-shaped magnetic steel strip 11 of a proper width and winds the cutpieces 110 into a wound core 12. The apparatus consists of a supportingmeans 20 for rotatably holding the magnetic steel strip 11 such as anuncoiler, a feeding in means 30 for feeding the magnetic steel strip 11into the subsequent process, a first metering means 40 for metering thelength of the fed in strip 1 1, a cutting means 150 provided with acutter 151 for cutting the fed in steel strip 11 into a prescribedlength of pieces of magnetic steel strip 11a in response to the outputfrom the metering means 40, a hump forming means 60 for making thecontinuous cutting operation easy, a feeding out means 70 for feedingout the cut pieces 11a of the magnetic steel strip, and a continuouswinding means 80 for winding the cut pieces 11a of the magnetic steelstrip into a wound core 12.

In operation, the hoop shaped magnetic steel strip 11 supported on therotatable supporting means 20 is fed into the cutting means 150 providedwith a cutter 151 through a couple of feed rollers 31 and 32 of thefeeding in means 30. At this moment, the length of the fed steel strip11 is metered with a metering means 40 consisting of, e.g., a feedroller 41 disposed between the supporting means 20 and the cutting means150 and the meter 42 connected therewith. In response to the output ofthe metering means 40, the cutting means 150 provided with the cutter151 is operated to cut the magnetic steel strip 1 1 into the prescribedlength of cut pieces 110. Thus, a plurality of cut pieces 1 la of themagnetic steel strip 11 are obtained. The length of the cut pieces 11ais so made that the first one is l, and the second one is l+21rt, andthen the third one is I+41rr and so on. The cut pieces 1 1a are then fedout with the feeding out means 70.

In the cutting process wherein the magnetic steel strip 11 is cut intopieces by the cutting means provided with a cutter 151, the hump formingmeans 60 disposed at the feedout side of the cutting means 150 forforming a hump in the strip 11 is utilized as shown in FIG. 7 in orderto continuously cut the strip 11 and feed the cut pieces 11a out towardsthe winding means 80 without stopping the feeding in operation.

Now the operation of the compulsory hump forming means 60 will bedescribed. The hump forming means 60 comprises a couple of hump formingmembers 61 and 62 one of which has a positively curved surface and theother of which has a negatively curved surface and a driving means formoving at least one of the couple of members 61 and 62 up and down. Thecouple of hump forming members 61 and 62 are normally disposed toprovide a spacing for passing the magnetic steel strip therethrough asshown in FIG. 6 so that the fed in strip 11 is humped between the upperhump forming member 62 and the lower hump forming member 61. When thecutting means 150 is operated to cut the strip 11 in response to theoutput of the metering means 40, the compulsory hump forming means 60 isoperated to release the strip 11 therein as shown in FIG. 7. When thehump forming 60 is operated to release the strip 11, that is, when thelower hump forming member 61 is retracted downward, the magnetic steelstrip 11 is temporarily stopped until the superfluous length at the humpis transferred into the feeding out means 70. While the magnetic steelstrip 11 is stopped at the cutting means 150, the cutter 151 cut thestrip 11 into the piece 11a of the magnetic strip. Since the strip 11 iscontinuously fed into the cutting means 150 while the cutter 151 iscutting the strip 11, there is formed another hump at the cutting means150. That is, the hump is formed since the end of the strip 11 isstopped by the cutter blade while the strip 11 is continuously fed in bythe feed-in roller 30. After the cutter 15 1 completed the cuttingoperation, the humped strip 11 is straightened by the elasticity thereofand the straightened strip 11 is again humped by the compulsory humpingmeans 60. By repeating the above serial operations, the magnetic steelstrip 11 is cut into the pieces of the steel strip 110 of the prescribedlength continuously without stopping the feed-in operation of thefeeding in means 30.

The cut pieces 1 1a of the magnetic steel strip 11 cut into theprescribed length are continuously fed out toward the continuous windingmeans through a couple of feed rollers "l1 and 72 of the feeding outmeans 70. In the continuous winding means 80, a plurality of pulleys 82,$3, 84, d5, 86 and 8'7 are disposed around a spool 81 and an endlessbelt m3 is guided along the path around the spool 81 and the pulleys 82,83, dd, M, as and b7. A tension exerting means 89 is disposed to exerttension on the endless belt 8% running around the pulleys M2, @33, Ml,d5, $6 and $7. The plurality of pieces llla of the magnetic steel striplll fed into the winding means M) are wound into a wound core and end ofthe last piece Illa of the strip 111 is fixed to the core byspot-welding. Thus, the wound core is completed.

In accordance with the above-described method of making a wound core, itbecomes possible to easily and rapidly make a wound core with highefficiency through a serial process from a hoop-shaped magnetic steelstrip 11.

In order to make a wound core as shown in FIGS. 1, 2 and 3 wherein theseam positions are out of alignment with one another by overlapping theend of the pieces lllla of the strip 1 l, the running speed V of theendless belt 38 of the winding means Ml is made higher than the speed Vof the feeding of the strip at the feeding out means 70 and the feedingin means 30 by the speed corresponding to the length W of the strip 11so that the overlapped length may be as long as W.

Instead of the above-described method wherein the speed V, is madehigher than the speed V so that the speed at the winding means may behigher than the speed at the feeding in and feeding out means, a methodcan be effected wherein the both speeds are made equal and the thicknessof the cutter blade of the cutter l5ll at the cutting means 150 is madeas thick as W as shown in FIG. 8 so that there may be spacings betweenthe adjacent pieces lllla fed through the feeding out means. Thus, theoverlapping of the pieces 11a in the wound core can be easily obtained.

In the case of making a wound core as shown in FIGS. 2 and 3 wherein theseam positions are within a limited range as that the wound core may beeasily disassembled, the feeding in means 30 and the cutting means 150are stopped after the first group of the cut pieces of the magneticsteel strip is wound up by the continuous winding means 80, and thefeeding in means 30 and the cutting means 150 are started to be operatedagain when the end of the first piece in the first group now wound in ahalf wound core comes to the position aligned with the end of the firstpiece of the second group to be wound.

The respective means constructing the apparatus 111MB for making thewound core will be described in detail referring to FIGS. 9 through 112.

The supporting means 20 is shown in FIG. 9 which shows an embodimentthereof. A rotatable frame 22 is mounted on a supporting framework 21.On the rotatable frame 22 are provided supporting members 23 for holdingthe magnetic steel strip 111 in a hoop shape. A loop controller 24 forcontrolling the loop of the fed out strip 11 is mounted on thesupporting framework 21. According to the angle of the loop controller2d, the magnitude of the loop is detected and the motor (not shown) forrotating the rotatable frame 22 is operated to be started and stopped.

The feeding in means 30 for the magnetic steel strip Til, the firstmetering means 40, the cutting means llfil] for cutting the strip 111into the prescribed length of pieces lllla of strip, the compulsory humpforming means 60 and the feeding out means 7th for feeding the piecesIlla of the strip into the winding means 30 are mounted on a base 101 asshown in FIG. 10.

The strip feeding in means 30 is constructed for instance by a guideroller 34!, and a couple of pairs of feed rollers 31 and 32 mounted in aframework 33. The metering means for metering the strip 11 isconstructed by a pair of metering rollers il disposed between the feedrollers 31 and 32 of the feeding in means 30 and a meter d2 connectedwith the metering rollers ii. The meter 42 is electrically connectedwith the cutting means 150 for actuating the cutting means 150 with theoutput thereof. The position for metering the length of the fed in striplll is not always required to be in the feeding in means 3t), but may bein the cutting means llfill just before the cutter therein.

As the meter d2, of the metering means M, a pulse generator as shown inFIG. 12 is used for instance. The pulse generator comprises a lightsource 43, a phototransistor M to receive the light from the lightsource d3, a lens Mb to condense the light from the light source d3, 2.light interceptor dill having a hole Alba to pass the condensed lighttherethrough. and a disc M! which has a plurality of slits to pass thelight thercthrough and is rotated in meshing engagement with themetering rollers M. The pulse in a sinewave form detected by thephototransistor M is amplified by the amplifier 415i and put into thecounter 417 through the Schmitt trigger as which shapes the pulse in asinewave form into a pulse of rectangular shape. By the counter 47, thelength of the magnetic steel strip 111 fed into the cutting means ismetered, e.g., by making one pulse correspond to 0.1 mm. of the strip11. At the moment when the counter 37 meters the prescribed length ofthe strip llll, the counter 4W is operated to transmit the output to theoperation control circuit (not shown) of the cutting means 115i As themeter 42 of the metering means so, a step motor and the like can be usedinstead of the above-described construction as shown in FIG. 12.

The cutting means operated in response to the output from the meteringmeans 45'!) is constructed as shown in FIG. MD for instance. In theconstruction shown in FIG. ill a supporter is vertically mounted on abase 1M, and on the supporter 1553 there are mounted a lower cutterblade 11% and a guide 153 for guiding a holder 1W2 holding an uppercutter blade i511 slidably moved up and down. The cutter holder 1152 isconnected with a cutter driving means use. As for the cutter drivingmeans 1156, a cylinder operated by compressed air is used for instancein order to quickly move the cutter blade 1151. The cutter driving means156 and the cutter holder 152 holding the cutter TM are connected witheach other through a first and second levers 157 and 15b fortransmitting the movement from the fonner to the latter. At the axis ofrotation 159 of the first lever 157 is mounted a bearing loll). Thebearing lltii) is engaged with a groove 163 provided on the slidablemember 162 which is slided by an auxiliary driving means 161. Theauxiliary driving means 161 is constructed by a cylinder operated bycompressed air and the like and is operated after the cutting operationis completed by the cutter 1151 in order to cut the magnetic steel strip11 under the same condition. The grove T63 of the slidable member M2 isformed in the shape of deformed Z so that the axis of rotation 159 ofthe first lever 1157 is moved up and down in response to the slidingmovement of the auxiliary driving means 161. On operation of the cuttingmeans as described above, when the cutter driving means 156 is movedleftward in F i0. 10 in response to the output of the metering meanstil, the first lever 1157 and the second lever 11533 are rotated aboutthe axis 159 in the counterclockwise and clockwise directionsrespectively and the cutter blade llfl ll is moved down to cut themagnetic strip llll running thereunder. When the first lever 157 reachesthe left end of the stroke thereof, the lever 157 actuates a microswitchSW which is electrically connected to the control circuit (not shown)for the power of the auxiliary driving means 161 and then the auxiliarydriving means M51. is operated. In response to the operation of theauxiliary driving means M51 wherein the slidable member 162 is slidedleftward, the axis of rotation 159 of the first lever 157 in engagementwith the groove I63 of the slidable member 162 is moved up. According tothe moving up of the axis 159 of the first lever 157, the first lever157 itself and the second lever lSh are also moved up. The moving up ofthe first lever 157 and the second lever 11% is detected by themicroswitch SW The detection by the microswitch SW is transmitted to thecutter driving means R56 and the driving means 156 is moved back to theright. When the cutter driving means R56 is moved to the right end torotate the first lever 157 clockwise to the limit end thereof, themicroswitch SW is actuated by the first lever 157. In

response to the actuation of the microswitch SW which detects the end ofthe backward movement of the cutter driving means 156, the auxiliarydriving means 161 is slided leftward to let down the levers 157 and 158so that the whole construction is set back to its original state. inaccordance with the above-described serial operation of the cuttingmeans 150, the upper cutter blade 151 is made to be operated to cut themagnetic strip 11 only when the first lever 157 is rotatedcounterclockwise by the cutter driving means 156, that is, only underone condition.

The hump forming means 60 is disposed at the feed out side of thecutting means 150 and comprises a couple of hump forming members 61 and62 one of which has a positively curved surface and the other of whichhas a negatively curved surface and-a driving means 63 such as acylinder operated by compressed air for moving at least one of thecouple of members 61 and 62 up and down. The couple of hump formingmembers 61 and 62 are so disposed that there may be a spacing betweenthe both members for providing a hump on the strip 11 runningtherethrough. As described above, the hump forming means 60 helps thecutting means 150 to continuously cut the magnetic steel strip 11without stopping the feeding in and feeding out of the strip 1 1 byforming a hump and releasing the strip 11.

The feeding out means 70 for feeding out the pieces of the magneticsteel strip 11 is constructed by a couple of pairs of pinch rollers 72and 73 provided in a framework 71 like the feeding in means 30 asdescribed above and a guide plate 74 fixed to the framework 71 therein.Other than the above elements, a belt-conveyor and the like may beemployed in the construction. In the case that the feeding speed of thefeeding out means 70 is equal to the winding space of the winding means80, the pinch rollers 72 and 73 may be ordinary feeding rollers. But inthe case that there is difference in speed, e.g., when the winding speedis higher than the feeding out speed, it is required that the pinchrollers 72 and 73 should be provided with means for enabling therotation of the rollers at the speed higher than the feeding speed. Asfor such a means, a ratchet mechanism can be utilized for instance.

On the feed-in side of the cutting means 150, there is provided aguiding means 50 which comprises a pair of guiding plates 51 and 52 anda driving means 53 such as a cylinder operated by compressed air formoving at least one (guide plate 52 in the case of the example shown inFIG. of the guide plates 51 and 52 up and down to close and open theguiding means 50. The guiding means 50 is operated so that by theopening operation thereof it allows the magnetic steel strip 11 runningtherethrough to hump when the cutter blade 151 is moved down to cut thestrip 11, and by the closing operation thereof it feeds the humped stripquickly into the cutting means by straightening the strip just after thecutting means 150 has completed the cutting operation.

The feed roller 31 and 32 of the feeding in means 30 and the pinchrollers 72 and 73 of the feeding out means 70 are provided with bevelgears 31b, 3272b, and 73b on the axes of rotation 31a, 32a, 72a and 73athereof respectively. The bevel gears 31b, 32b, 72b and 73b are inmeshing engagement with the bevel gears 31c, 32c, 72c respectively and73c fixed on the driving shafts 107 and 108 connected through a clutch110. The shaft 108 and accordingly the shaft 107 are driven by the powersource 102 through a gear train consisting of gears 102a, 102b, 1020, ashaft 103, pulleys 10S and 106 around which a belt 104 and the like isrunning.

The clutch 110 coupling the driving shafts 107 and 108 is operated whenthe wound core of the type as shown in FIGS. 2 and 3 is wound and whenthe hoop-shaped magnetic steel strip 11 is all fed out and a new hoop isrequired to be mounted at the supporting means 20, in order totemporarily stop the feeding in means 30.

The above-mentioned power source 102 is connected to the winding means80 so as to drive and rotate the same through a shaft 1 11 having abevel gear l02b at an end thereof and a pulley 112 at the other endthereof and a belt 113 running around the pulley 112. The shaft 111 fordriving the continuous winding means 80 is connected with a secondmetering means 1 15 which meters the length of the strip piece Ma woundby the winding means 80. The second metering means 115 is disposed inrelation with the rotation of the spool 81 about the axis of rotation 95and related with the microswitch SW. which is actuated at the beginningof winding. Thus the second metering means 115 makes it easy to makesuch a wound core as shown in FIGS. 2 and 3.

The continuous winding means 80 for continuously winding the pieces ofmagnetic steel strip 11 cut in the prescribed size and fed out from thefeeding out means continuously will now be described in detail withreference to a preferred embodiment thereof shown in FIG. 11. Aframework 91 is mounted on a base 90 and is provided with a rotatablespool 81 and a plurality of pulleys 82, 83, 84, 85, 86 and 87. Anendless belt 88 is disposed to run around the pulleys 82 through 87 andthe spool 81 in the shape to receive the fed out pieces 11a of themagnetic strip 1 l. The rotation of the power source 102 is transmittedto the pulley 83 through a belt 1 13, an intermediate pulley 114, and abelt 115. The transmitted rotation on the pulley 83 is furthertransmitted to the spool 81 and the pulleys 82, 84, 85, 86 and 87. Thus,the pieces 1 1a of the magnetic steel strip 11 fed out from the feedingout means and into the winding means are wound into a wound core on thespool 81.

The pulleys and 86 are supported on a pulley carrier 94 which is slidedin a slide guide 93 by a tension exerting means 89, so that the pulleys85 and 86 exert tension on the endless belt 88. And by the tensionexerted on the endless belt 88, the pieces 11a of the of the magneticsteel strip 11 are tightly wound on the spool 81 so that the wound coremay be obtained in a good condition and the wound core may be easilyremoved from the spool 81 by warming it. The spool 81 is mounted on aspool holding member 97 which is slided in a slide guide 96. The spoolholding member 97 is slided by an operating means 92 for sliding themember 97 together with the spool 81 mounted thereon, so that theincrease in the diameter of the wound core on the spool is compensated.In response to the increase in the diameter of the wound core on thespool, the length of the loop of the endless belt 88 around the core isalso increased This increase in the length of the loop is compensated bythe move of the tension exerting means 80. That is, by the rightwardmovement of the tension exerting means 89, a constant tension can bealways obtained on the endless belt 88 regardless of the loop size ofthe endless belt. Thus, the pieces 11a of the magnetic steel strip 11are wound on the spool in a constant tightness. In order to guide thepieces 11a of magnetic steel into the winding means with certainty, aguide plate 98:: held by a holding spring 98b may be provided betweenthe pulleys 82 and 83. By this disposition of the guide plate 980 thepieces 11a of the magnetic steel strip 11 fed out of the feeding outmeans 70 are guided between the guide plate 98a and the endless belt 88running around the pulley 82 without fail.

A microswitch SW is disposed in relevant to the axis of rotation of thespool 81 so that the position of winding start of the pieces 11a of themagnetic steel may be detected thereby. By the operation of themicroswitch SW and the second metering means 115, the clutch 110 isoperated or released to temporarily stop or start again the feeding inmeans 30. Thus, the seam positions in the wound core can be easily madeto exist in a limited range and the feeding in means 30 can be easilystopped when the hoop-shaped magnetic steel strip is supplemented.

in the case that the wound core as shown in FIGS. 2 and 3 is made, themicroswitch SW disposed in relevant to the axis of rotation of the spool81 and the second metering means for metering the wound length areeffectively utilized.

In other words, in the case of making the wound core as shown in FIGS. 2and 3, it is necessary to temporarily stop the feeding of the magneticsteel strip 11 by the feeding in means 30 by means of the clutch everytime the group of the pieces lie of the magnetic steel is finishedwinding until the starting position of the winding of the next pieceElla comes to the position in alignment with the starting position ofthe winding of the first piece in the previous group. And in order tostop the feeding of the magnetic steel strip ll ii, the microswitch SW,is used to operate the clutch illfl. in such a case, the clutch llli)should not be operated just after the microswitch SW is actuated butshould be operated after the second metering means M5 meters aprescribed length of the winding. Now the above-described operation willbe described with respect to an example. in the case that the internaldiameter of the wound core is 200 mm. the thickness of the pieces of themagnetic steel is 0.35 mm. and the number of the pieces in one group ofthe pieces is 10, the length of the first piece of the magnetic steelstrip on the innermost convolution of the wound core is 200 11mm. andthat of the last piece of the magnetic steel strip on the outermostconvolution is 200-l-(2 X0.3 X) vrmm. and then there is 7 11mm.difference in length between the both. Accordingly, the clutch llllflshould be operated after the spool til is rotated by 7 rrmm. furtherafter the microswitch SW, is actuated in order that the subsequentpieces may be fed into the winding means in the right position where thestarting position of winding of the first pieces of the respectivegroups are in alignment with one another. In the case of the windingbetween the second and third groups, the second metering means 11115 isused for making the clutch llltl operate after the spool 81 is rotatedby 71r 2 mm. after the microswitch SW is actuated. In the case of thewinding of the pieces between the third and the fourth groups, thefurther rotation of the spool should be 71r 3 mm. Thus, the clutch liftis operated after the prescribed length of strip was me tered by themetering means so as to make the initial position of the winding of therespective groups be in a limited range.

The second metering means 115 may not always be disposed on the shaft111 as shown in H6. ill, but may be for instance disposed in relevant tothe pulley d2, 83, 84, $5, $65 and 37 or the endless belt 80. That is,the second metering means llllfi may be disposed at any position wherethe abovedescribed prescribed length of the strip can be metered.

it is apparent that the continuous winding means d0 driven by the commonpower source 102 in the embodiment shown in the drawing may be driven byan independent power supply.

Since the apparatus for making the wound core in accordance with thepresent invention is constructed out of the means as describedhereinabove, it becomes possible to make a wound core easily through aseries of processes by continuously cutting a hoop-shaped magnetic stripinto prescribed length of pieces and winding them up into a convolution.

We claim:

ll. Method of making a wound core comprising the steps of feeding ahoop-shaped magnetic steel strip rotatably supported by a supportingmeans continuously into a cutting means provided with a cutter whichcuts said strip into prescribed length of pieces of magnetic steel, saidcutting means being operated in response to the output of a firstmeterin g means which meters the length of said strip fed into saidcutting means, cutting said magnetic steel strip continuously into theprescribed length of pieces of magnetic steel by means of said cutterwithout stopping the feeding of said strip utilizing a hump of saidstrip formed by a hump forming means, said hump forming means beingprovided on the downstream of said cutting means and forming a hump insaid magnetic strip before the cutting operation of said cutting meansand releas ing said hump formed at the beginning of cutting operationand moving back to form a hump again at the end of cutting operation,feeding the pieces cut out of said magnetic strip into a continuouswinding means by means of a feed-out means, and winding said pieces ofmagnetic steel by said continuous winding means so that the seampositions between the adjacent pieces may be out of alignment with oneanother.

2. Method of making a wound core as defined in claim 1 wherein thewinding speed of said continuous winding means is made slightly higherthan the feeding speed of said feed out i llll means so that the seampositions between the pieces of magnetic steel may be out of alignmentwith one another by the difference in speed.

3. Method of making a wound core as defined in claim 11 wherein saidcutter in the cutting means is made to out said strip in the differentlength so that the difference in length may arrange said pieces in saidwound core in the arrangement out of alignment with one another.

3. Apparatus for making a wound core comprising a. a supporting meansfor rotatably supporting a hoopshaped magnetic steel strip,

b. a feed in means for continuously feeding said magnetic steel strip,

c. a first metering means for metering the length of said magnetic steelstrip fed by said feed-in means,

d. a cutting means including a cutter for cutting said magnetic steelstrip into the prescribed length in response to the output of saidmetering means,

e. a compulsory hump forming means disposed at the downstream of saidcutting means for forming a prescribed hump in said magnetic steelstrip, said compulsory hump forming means forming a prescribed humpnormally in the magnetic steel strip before being cut, releasing thehump at the beginning of the cutting operation, and moving back to forma hump again at the end of the cutting operation so that said magneticsteel strip may be continuously cut into the prescribed length ofpieces,

f. a feed-out means for feeding the cut pieces of magnetic steel cut bysaid cutter of the cutting means, and

g. a continuous winding means for winding said pieces of magnetic steelinto a core wherein the seam positions between the pieces are out ofalignment with one another.

5. Apparatus for making a wound core as defined in claim 4 wherein acommon power source is disposed for driving said feed-in means, saidfeed-out means and said continuous winding means, and a clutch isdisposed for connecting the driving shafts of said feed-in means andfeed-out means.

ti. Apparatus for making a wound core as defined in claim d wherein twoindependent power sources are disposed for respectively driving saidfeed-in means and said feed-out and winding means, and a clutch isdisposed for connecting said feed-in means and said feed-out means.

7. Apparatus for making a wound core as defined in claim d wherein saidfirst metering means comprises a metering roller rotating in contactwith said magnetic steel strip and a meter of pulse generator typeconnected with said metering roller.

8. Apparatus for making a wound core as defined in claim t wherein saidcutting means comprising a holder for holding said cutter, a supportingmember for supporting a guide by which said holder is guided up anddown, a cutter driving means for operating said cutter secured to saidholder, a first and a second lever interlocking said cutter drivingmeans with said holder in said guide for transmitting the movement ofsaid cutter driving means to said cutter, and an auxiliary driving meansfor moving said cutter up and down after the cutting operation throughsaid first and second levers.

5". Apparatus for making a wound core as defined in claim 3 wherein saidcutter in said cutting means has thickness enough to cut off themagnetic steel strip of the length required to make the seam positionsin the wound core be out of alignment with one another.

Ml. Apparatus for making a wound core as defined in claim 4i wherein asteel strip guide means is disposed at the upstream of said cuttingmeans for letting the magnetic steel strip be humped when said cuttingmeans is operated to cut said strip and feeding forward said strip whensaid cutting means finished cutting operation.

llll. Apparatus for making a wound core as defined in claim 4 whereinsaid compulsory hump forming means comprises a couple of hump formingmembers one of which has a positively curved surface and the other ofwhich has a negatively curved surface and a driving means for moving atleast said to receive said pieces of magnetic steel to be wound thereon,said belt being made to vary the diameter of the loop thereof aroundsaid spool, and a tension exerting means for exerting tension on saidendless belt, whereby said endless belt is driven by at least one ofsaid pulleys and said spool is made to rotate towind said pieces ofmagnetic steel.

l h II t III

1. Method of making a wound core comprising the steps of feeding ahoop-shaped magnetic steel strip rotatably supported by a supportingmeans continuously into a cutting means provided with a cutter whichcuts said strip into prescribed length of pieces of magnetic steel, saidcutting means being operated in response to the output of a firstmetering means which meters the length of said strip fed into saidcutting means, cutting said magnetic steel strip continuously into theprescribed length of pieces of magnetic steel by means of said cutterwithout stopping the feeding of said strip utilizing a hump of saidstrip formed by a hump forming means, said hump forming means beingprovided on the downstream of said cutting means and forming a hump insaid magnetic strip before the cutting operation of said cutting meansand releasing said hump formed at the beginning of cutting operation andmoving back to form a hump again at the end of cutting operation,feeding the pieces cut out of said magnetic strip into a continuouswinding means by means of a feed-out means, and winding said pieces ofmagnetic steel by said continuous winding means so that the seampositions between the adjacent pieces may be out of alignment with oneanother.
 2. Method of making a wound core as defined in claim 1 whereinthe winding speed of said continuous winding means is made slightlyhigher than the feeding speed of said feed out means so that the seampositions between the pieces of magnetic steel may be out of alignmentwith one another by the difference in speed.
 3. Method of making a woundcore as defined in claim 1 wherein said cutter in the cutting means ismade to cut said strip in the different length so that the difference inlength may arraNge said pieces in said wound core in the arrangement outof alignment with one another.
 4. Apparatus for making a wound corecomprising a. a supporting means for rotatably supporting a hoop-shapedmagnetic steel strip, b. a feed in means for continuously feeding saidmagnetic steel strip, c. a first metering means for metering the lengthof said magnetic steel strip fed by said feed-in means, d. a cuttingmeans including a cutter for cutting said magnetic steel strip into theprescribed length in response to the output of said metering means, e. acompulsory hump forming means disposed at the downstream of said cuttingmeans for forming a prescribed hump in said magnetic steel strip, e''.said compulsory hump forming means forming a prescribed hump normally inthe magnetic steel strip before being cut, releasing the hump at thebeginning of the cutting operation, and moving back to form a hump againat the end of the cutting operation so that said magnetic steel stripmay be continuously cut into the prescribed length of pieces, f. afeed-out means for feeding the cut pieces of magnetic steel cut by saidcutter of the cutting means, and g. a continuous winding means forwinding said pieces of magnetic steel into a core wherein the seampositions between the pieces are out of alignment with one another. 5.Apparatus for making a wound core as defined in claim 4 wherein a commonpower source is disposed for driving said feed-in means, said feed-outmeans and said continuous winding means, and a clutch is disposed forconnecting the driving shafts of said feed-in means and feed-out means.6. Apparatus for making a wound core as defined in claim 4 wherein twoindependent power sources are disposed for respectively driving saidfeed-in means and said feed-out and winding means, and a clutch isdisposed for connecting said feed-in means and said feed-out means. 7.Apparatus for making a wound core as defined in claim 4 wherein saidfirst metering means comprises a metering roller rotating in contactwith said magnetic steel strip and a meter of pulse generator typeconnected with said metering roller.
 8. Apparatus for making a woundcore as defined in claim 4 wherein said cutting means comprising aholder for holding said cutter, a supporting member for supporting aguide by which said holder is guided up and down, a cutter driving meansfor operating said cutter secured to said holder, a first and a secondlever interlocking said cutter driving means with said holder in saidguide for transmitting the movement of said cutter driving means to saidcutter, and an auxiliary driving means for moving said cutter up anddown after the cutting operation through said first and second levers.9. Apparatus for making a wound core as defined in claim 4 wherein saidcutter in said cutting means has thickness enough to cut off themagnetic steel strip of the length required to make the seam positionsin the wound core be out of alignment with one another.
 10. Apparatusfor making a wound core as defined in claim 4 wherein a steel stripguide means is disposed at the upstream of said cutting means forletting the magnetic steel strip be humped when said cutting means isoperated to cut said strip and feeding forward said strip when saidcutting means finished cutting operation.
 11. Apparatus for making awound core as defined in claim 4 wherein said compulsory hump formingmeans comprises a couple of hump forming members one of which has apositively curved surface and the other of which has a negatively curvedsurface and a driving means for moving at least said hump forming memberhaving a positively curved surface up and down.
 12. Apparatus for makinga wound core as defined in claim 4 wherein said continuous winding meanscomprises a rotatable and movable spool, a plurality of pulleys disposedaround said spool, an endless belt running around said pulleys and alongalmost all the periphery of said spool except the portion to reCeivesaid pieces of magnetic steel to be wound thereon, said belt being madeto vary the diameter of the loop thereof around said spool, and atension exerting means for exerting tension on said endless belt,whereby said endless belt is driven by at least one of said pulleys andsaid spool is made to rotate to wind said pieces of magnetic steel.